<template>
  <div class="camera_outer">
    <video id="videoCamera" :width="videoWidth" :height="videoHeight" autoplay></video>
    <canvas style="display:none;" id="canvasCamera" :width="videoWidth" :height="videoHeight" ></canvas>
<!--    <img src="../assets/img/camera_01.png" alt="" class="bg_r_img">-->
    <div v-if="imgSrc" class="img_bg_camera">
      <img :src="imgSrc" alt="" class="tx_img">
      <div class="img_btn_camera">
        {{validTip}}<img v-if="validTip === '验证中'" src="../assets/img/loding.svg" alt="" class="loding_img">
      </div>
    </div>
    <div v-else class="btn_camera">把您的脸至于圆圈中央</div>

  </div>
</template>
<script>
export default {
  data () {
    return {
      videoWidth: 540,
      videoHeight: 410,
      imgSrc: '',
      thisCancas: null,
      thisContext: null,
      thisVideo: null,
      validTip: '验证中'
    }
  },
  computed: {
  },
  methods: {
    /*
     *@author wf_Huang
     *@Time 2019/6/5 0005 17:35
     *@function  调用权限
     *****************************************/
    getCompetence () {
      var _this = this
      this.thisCancas = document.getElementById('canvasCamera')
      this.thisContext = this.thisCancas.getContext('2d')
      this.thisVideo = document.getElementById('videoCamera')
      // 旧版本浏览器可能根本不支持mediaDevices，我们首先设置一个空对象
      if (navigator.mediaDevices === undefined) {
        navigator.mediaDevices = {}
      }
      // 一些浏览器实现了部分mediaDevices，我们不能只分配一个对象
      // 使用getUserMedia，因为它会覆盖现有的属性。
      // 这里，如果缺少getUserMedia属性，就添加它。
      if (navigator.mediaDevices.getUserMedia === undefined) {
        navigator.mediaDevices.getUserMedia = function (constraints) {
          // 首先获取现存的getUserMedia(如果存在)
          var getUserMedia = navigator.webkitGetUserMedia || navigator.mozGetUserMedia || navigator.getUserMedia
          // 有些浏览器不支持，会返回错误信息
          // 保持接口一致
          if (!getUserMedia) {
            return Promise.reject(new Error('getUserMedia is not implemented in this browser'))
          }
          // 否则，使用Promise将调用包装到旧的navigator.getUserMedia
          return new Promise(function (resolve, reject) {
            getUserMedia.call(navigator, constraints, resolve, reject)
          })
        }
      }
      var constraints = { audio: false, video: { width: this.videoWidth, height: this.videoHeight, transform: 'scaleX(-1)' } }
      navigator.mediaDevices.getUserMedia(constraints).then(function (stream) {
        // 旧的浏览器可能没有srcObject
        if ('srcObject' in _this.thisVideo) {
          _this.thisVideo.srcObject = stream
        } else {
          // 避免在新的浏览器中使用它，因为它正在被弃用。
          _this.thisVideo.src = window.URL.createObjectURL(stream)
        }
        // eslint-disable-next-line no-unused-vars
        _this.thisVideo.onloadedmetadata = function (e) {
          _this.thisVideo.play()
        }
      }).catch(err => {
        console.log(err)
      })
    },
    /*
     *@author wf_Huang
     *@Time 2019/6/5 0005 17:32
     *@function  绘制图片
     *****************************************/
    setImage () {
      var _this = this
      // 点击，canvas画图
      _this.thisContext.drawImage(_this.thisVideo, 0, 0, _this.videoWidth, _this.videoHeight)
      // 获取图片base64链接
      var image = this.thisCancas.toDataURL('image/png')
      _this.imgSrc = image
      this.$emit('refreshDataList', this.imgSrc)
    },
    /*
     *@author wf_Huang
     *@Time 2019/6/5 0005 17:44
     *@function  base64转文件
     *****************************************/
    dataURLtoFile (dataurl, filename) {
      var arr = dataurl.split(',')
      var mime = arr[0].match(/:(.*?);/)[1]
      var bstr = atob(arr[1])
      var n = bstr.length
      var u8arr = new Uint8Array(n)
      while (n--) {
        u8arr[n] = bstr.charCodeAt(n)
      }
      return new File([u8arr], filename, { type: mime })
    },
    /*
     *@author wf_Huang
     *@Time 2019/6/10 0010 3:41
     *@function  关闭摄像头
     *****************************************/
    stopNavigator () {
      this.thisVideo.srcObject.getTracks()[0].stop()
    }
  },
  mounted () {
    this.getCompetence()
  },
  beforeDestroy () {
    this.stopNavigator()
  }
}

</script>
<style lang="scss" scoped>
.camera_outer{
  position: relative;
  overflow: hidden;
  //background: url("../../assets/img/user_0608_04.png") no-repeat center;
  background-size: 100%;
  video,canvas,.tx_img{
    -moz-transform:scaleX(-1);
    -webkit-transform:scaleX(-1);
    -o-transform:scaleX(-1);
    transform:scaleX(-1);
  }
  .btn_camera{
    position: absolute;
    bottom: 4px;
    left: 0;
    right: 0;
    height: 50px;
    background-color: rgba(0,0,0,0.3);
    line-height: 50px;
    text-align: center;
    color: #ffffff;
  }
  .bg_r_img{
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    top: 0;
  }
  .img_bg_camera{
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    top: 0;
    img{
      width: 100%;
      height: 100%;
    }
    .img_btn_camera{
      position: absolute;
      bottom: 0;
      left: 0;
      right: 0;
      height: 50px;
      line-height: 50px;
      text-align: center;
      background-color: rgba(0,0,0,0.3);
      color: #ffffff;
      .loding_img{
        width: 50px;
        height: 50px;
      }
    }
  }
}
</style>
